Drum frictioning device



1934- R. J. o. SIMPSON 7,

DRUM FRICTIONING DEVICE Filed Jan. 24, 1954 Patented Oct. 23, 1934 PATENT OFFICE DRUM FRICTIONING DEVICE Robert J; 0. Simpson, Athol, Mass, assignor to The L. S. Starrett Company, Athol, Mass., a corporation of Massachusetts Application January 24, 1934, SerialNo. 708,115

11 Claims.

This invention relates primarily to measuring tapes, although the principles involved are applicable to a wide range of winding. and'reeling apparatus, as fishing line reels, dental floss dis- ,pensers, chalk markers and the like.

Considering the tape measure as typical however the tape drum has the undesirable effect of spinning or overrunning whenever the tape tends to back lash. This has long been recognized as an objectionable feature in this and related arts and various forms and arrangements of spring friction devices have been devised to overcome it.

The construction of the spring and its method of assembly in the tape case has of necessity varied according to the structure of the particular drum and case. involved.

In all instances, however, the essential function .of the spring was to offer a yielding resistance to the unwinding actionof the drum.

In some instances the spring has been assembled torotate with the drum with some-part of. the spring frictioning on the adjacent Wall of a .the tape case. In other instances, the spring has been fixed on. the tape case wall-with its free end 5 frictioning on the rotating drum.

Where the tape case-was of the single bearing type with the drum journaled in one wall only of the case, the spring was assembled withinthe case in such manner as to tend to force the flange of the drum into contact with the opposite wall ofthe case.

Where thecase was of the double bearing type, with the drum .journaled in both walls of the case, the spring was assembled within the case insuch manner as to tend to force theljfiange of the drumv away from the wall of the case opposite to the wall against which the spring reacted.

. My invention is particularly. applicable to the double-bearing type of tape casealthough not necessarily limited thereto. According to it the friction spring not only functions as a retarding or braking member to prevent spinning or overrunning of the drum in unwinding but also as a tension member adapted to'urge the drum towards the wall of the case-against which the spring refrom the detent'22 is indicated at 24.

Moreover, the drum assembly can be economically applied to standard tape reels and cases without requiring substantial re-design of existing structures and without requiring especially skilled assemblers. l

These, and many other features of advantage which will be readily apparentto those skilled in the art are secured in the device of the present invention. 7 I

For purposes of illustration, I show in theaccompanying drawing an embodiment of 'my inventionwhich I have found highly satisfactory under actual service conditions and well adapted. to the requirements of commercial manufacture.

Fig. l is an enlarged fragmentary section through a tape measure case of standard construction equipped with a drum frictioning device in accordance with my invention. I

Fig. 2 is a perspective view of the complete case, and i n Fig. 3 is a perspective view of my novel friction spring and associated parts, removed from the assembly. v

I have indicated at 10 the top or lever sidewall of a tape measurecase ofstandardtype andat180 11 the bottom or push side wall of such case. The Walls 10 and 11 may, if desired, be covered with any. suitable covering materialas indicated at 12 and 13. The case wallsandtheir covers, if covered, are centrally aperturedto receive the tape a reel. Such aperture atthe top wall of the caseis lined with the usual drum collar 14 which is fixed thereto in any suitable manner. Set withinsaid collar as a bearing is the revoluble winding and unwinding drum or tape reel 15. This includesa drum head or flange 16 and an axial hub or stud 17 fast with said head.

In the particular type of tape measure illustrated in the drawing thedrum is provided with a hinged winding lever or arm 18 adapted when the tape is not in use to be folded down and locked within the drum as in accordance with standard practice. The hinge or pintle for the winding arm is indicated at 19 and is shown as mounted on the outer face of the drum head. The handle of the winding armis indicated at 20 and is shown as folded down into the drum, the drum head 16 being suitably apertured as at 21 to'permit the handle to enter into the drum and be locked by the spring locking detent 22 so that the arm 18 -will lie substantially flush with the outer face of the drum head 16. The usual tape stud 23' is fixed to the inner face of the drum head and the push pin for disengaging the winding arm 18 -wall,- or its cover, of the tape case.

Thus far the construction described is standard. In order to prevent undesirable spinning of the drum due to back lash of the tape I combine with the drum a drum frictioning means of new type. The stud 17 through which the push pin 24 slides is axially bored and counterbored from the bottom towards the top side of the tape case and is tapped and threaded to receive the inner threaded end of a hollow stud screw 25 through which the push pin freely slides. Preferably the push pin is so formed as to prevent it from dropping entirely out of the assembly. As here shown, this is attained by axially recessing the inner end of the stud screw to provide a relatively shallow chamber 26 and forming. the push pin itself between its ends with roughened portions 27 which by contact with the bottom wall of the recess 26 limits the downward movement of said pin.

Encircling the base of the stud 17 and fast therewith is a stud sleeve 28 having a depending annular bearing portion 29 enclosing the adjacent shouldered portion 30 of the stud screw. The depending flange 29 provides with the overlying portion of the sleeve 28 an annular recess within which is entered the horizontally inturned portion 31 of a stud collar 32. The flanged outer portion 33 of said collar is fixed to the bottom If desired, a stud washer 34 of fibre or other suitable material may be interposed between the studsleeve 28 and the inturned portion 31 of the stud collar. A similar stud collar washer 35 may likewise be interposed between said portion 31 and a stud sleeve washer 36 surrounding the stud screw 25. Coiled about the shouldered portion 30 of the stud screw between the stud sleeve washer 36 and the flanged head 37 of the stud screw is a coil spring 38. One end of the spring is fixed to the stud screw. The other end is free to bear against the stud collar and offer frictional resistance to the unwinding action of the drum, thus preventing undesirable spinning of the drum, should the tape tend to back lash. Preferably the vertical wall of the stud collar is internally grooved as at 39 to receive said free end of the spring.

In operation, the tape drum stud l7 and the drum revolve as a unit. By reason of its screw threaded engagement with said stud 17, the stud screw 25 also revolves with the stud 17 as does the stud sleeve 28. The degree of compression of the coil spring 38 may be varied by changing the adjustment of the stud screw. When compressed and assembled as shown in Fig. 1 the spring reacts between the flanged head 37 of the stud screw 25 and the inturned portion 31 of the stud collar 32, or more accurately between the washer 36.and the flanged head 37 of the stud screw. Its tendency therefore is to force the stud sleeve 28 towards its bearing in the bottom wall of the case,

specifically towards the inturned portion 31 of,

Although I have shown my invention as ap--,

plied to a tape. case equipped with an internally- The stud bearing at both top and.

locking crank arm, it will be understood that the invention is not restricted thereto.

Various structural and functional modifications are possible according to the use and construction of the particular reel and reel case in which my invention may be installed. All such modifications are to be considered as within the purview of my invention, if within the limits of the appended claims.

What I therefore claim and desire to secure by Letters Patent is:-

1. In tape case construction, a case having top and bottom walls one of which is provided with a stud collar, a tape drum disposed in said case and having a stud. a stud screw extending through said collar and threaded to said stud, means carried by the stud frictionally cooperating with the stud collar, and a spring compressively confined and reacting between said stud screw and said stud collar to produce a yielding friction cooperation between said stud collar and 1 said means to resist rotation of said drum relative to said case.

2. A tape case construction as claimed in claim 1 wherein the stud collar has a flange surrounding the stud screw interiorly of the case and the means carried by the'stud frictionally cooperating with the stud collar comprises a sleeve fixed thereto and bearing upon said flange.

3. A tape case construction as claimed in claim 1 wherein the spring is coiled about and fastened at one end to the stud screw, the other end of the spring being free and rubbing against the inner face of the stud collar as a rotationretarder.

4.. In tape case construction, a case having top and bottom walls one of which is provided with a stud collar extending internally of the case and terminating in an inturned flange, a tape drum disposed in said case and having a stud provided with a'sleeve bearing upon the inner side of said inturned flange of the stud collar, a stud screw threaded to said stud and provided with a shouldered portion and'a head outwardly of the flange of said stud collar, and a coil spring surrounding said shouldered portion and compressively confined between the head of the screw and the inturned flange of the stud collar, a part of said spring engaging the inner face of the stud collar.

5. In tape case construction, a case having top and bottom walls one of which is provided with a stud collar extending internally of the case and terminating in an inturned flange, a tape drum disposed in said case and having a stud provided with a sleeve bearing on the inner side of said flange of the stud collar, said sleeve having an outwardly directed flange, a stud screw threaded to said stud and provided with a head and a shouldered portion outwardly of the flange of the stud collar, the flange of said sleeve abutting the shouldered portion of the stud screw, and a coil spring compressively confined between the head of the screw and the inturned flange of the stud collar, a part of said spring engaging the inner face of the stud collar.

6. A reel structure comprising a drum, a drum supporting element,-a stud unit carried by the drum and having a pair of spaced shoulders, the

drum supporting element being provided with a flange disposed between said shoulders, and resilient expansively acting means between said flange and one of said shoulders tending constantly to urge the stud unit axially toproduce frictional cooperation between said flange and the other of said shoulders.

'7. A reel structure comprising a drum, a drum supporting element, a stud unit carried by the drum and having spaced shoulders, the drum supporting element being provided with a flange disposed between said shoulders, and a compressed spring interposed between said flange and one of said shoulders and tending constant 1y to urge the stud unit axially to produce frictional cooperation between said flange and the other of said shoulders.

8. A reel structure comprising a drum, a drum supporting element, a stud carried by the drum, a stud screw threaded into the stud, a stud sleeve confined between the stud and the stud screw, the stud screw having a head spaced from said stud sleeve, a stud collar carried by the drum supporting element and having an annular flange interposed between the stud sleeve and the head of the stud screw, the stud sleeve having journal hearing within said annular flange, and a compressed spring confined between the head of the stud screw and the annular flange of the stud collar and tending constantly to urge the stud screw, the stud and the stud sleeve axially to produce frictional cooperation between the stud sleeve and the annular flange oi the stud collar.

9. A reel structure as set forth in claim 8 in which the drum supporting element comprises a case having spaced top and bottom walls, in which the stud collar is carried by one of said walls, and in which the other of said walls has a bearing in which the drum is guided for rotation and axial movement.

10. A reel structure comprising a drum, a drum supporting element, a stud unit carried by the drum, the drum supporting element being provided with an annular flange in which the stud unit is journaled, the stud unit including a flange overlying said annular flange at one side thereof, the stud unit also including a stud screw having a head at the other side of said annular flange, and resilient expansively acting means between said annular flange and the head of said stud screw tending constantly to urge the stud unit axially to produce frictional cooperation between said annular flange and the flange of said stud unit.

11. A reel structure comprising a case having top and bottom walls, a drum disposed within said case, a stud unit carried by the drum, one

of the walls of the case having a stud collar extending into the case and said stud collar being provided inwardly of the plane of said wall with an annular flange disposed substantially in a plane parallel with the plane of said wall, the stud unit being journaled in said annular flange and having a lateral flange overlying said annular flange inwardly thereof, said stud unit including a flange overlying said annular flange at the outer side thereof and disposed within said stud collar inwardly of the plane of the wall of the ease having said stud collar, and a spring interposed between the second mentioned flange of said stud unit and said annular flange and acting to urge the stud unit axially to produce frictional cooperation between the first mentioned flange of the stud unit and said annular flange.

ROBERT J. O. SIMPSON. 

